Rioting has spread across central Athens and buildings have gone up in flames amid mass protests as MPs prepare to vote on a crucial debt deal needed to prevent bankruptcy.

Clashes erupted across the city centre after more than 100,000 protesters marched to parliament to rally against drastic austerity cuts that will force firing in the civil service and slash the minimum wage.

Thick clouds of smoke and tear gas filled the air around parliament, as hundreds of rioters staged running battles with riot police and at least five buildings were in flames.